1155531312 has 320 divisors, whose sum is σ = 3768092160. Its totient is φ = 336669696.

The previous prime is 1155531271. The next prime is 1155531317. The reversal of 1155531312 is 2131355511.

1155531312 is a `hidden beast` number, since 115 + 5 + 531 + 3 + 12 = 666.

It is a super-2 number, since 2×1155531312² = 2670505226024882688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1155531317) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13922023 + ... + 13922105.

It is an arithmetic number, because the mean of its divisors is an integer number (11775288).

Almost surely, 2^1155531312 is an apocalyptic number.

1155531312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1155531312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1884046080).

1155531312 is an abundant number, since it is smaller than the sum of its proper divisors (2612560848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1155531312 is a wasteful number, since it uses less digits than its factorization.

1155531312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217 (or 205 counting only the distinct ones).

The product of its digits is 2250, while the sum is 27.

The square root of 1155531312 is about 33993.1068306502. The cubic root of 1155531312 is about 1049.3666057479.

Adding to 1155531312 its reverse (2131355511), we get a palindrome (3286886823).

The spelling of 1155531312 in words is "one billion, one hundred fifty-five million, five hundred thirty-one thousand, three hundred twelve".